Cross roller bit



April 1936- N. B. BERLETHY 2,038,408

CROSS ROLLER BIT Filed Feb. 18; 1955 Ale/son 5. 582/?! Fly; INVENTOR BY Am ATTORNEY Patented Apr. 21, 1936 UNITED STATES 7 2,038,408 cnoss ROLLER arr Nelson B. Berleth, Houston, Tex., assignor to Hughes Tool Company, Houston, Tex., a corporation of Texas Application February 18, 1935, Serial No.7,!!!"

7 Claims.

My invention relates to cross roller bits employed in drilling deep wells; The cross roller bit is characterized by a head having mounted at the forward end thereof a set of diametrical cross rollers which cut the center of the hole, and a, pair of opposed inclined side cutters to cut the gage of the hole.

It is an object of the invention to providea drill on which the side cutters-are mounted for rotation upon a removable bridge which can be replaced when worn.

I also desire to mount thecross rollers upon a removable and replaceable shaft. 7

It is the main object of the invention to provide a structure of the character stated in which Inthe drawing herewith, Fig. .1 is a central.

structed according to my invention,

Fig. 2 is an inner side view taken at right angles to the view seen in Fig. 1 and partly in section through the cross roller cutters.

Fig. 3 is a bottom plan view of the head and cutters.

Fig. 4 is a broken detail in side elevation. Fig. 5 is a broken view similar to Fig. 2 but longitudinal section through a bit head conshowing a slightly different embodiment of the invention.

The invention resides largely in the structural details of a cross roller bit. The head I is generally circular in outline. It has an upwardlytapered, threaded shank 2 for attachment to the drill collar. On the lower end are two opposite legs 3 and two opposite legs 4 set at 90 from the first set of legs 3. These legs enclose a recess or pocket 5 .in which the cutters are partially housed. I

The drill head is split longitudinally along a plane indicated by the line 6 in Fig. 1. The shank and head are formed with a water course I which has branching ducts 8, 8 and 9, 9 discharging upon the cutters. The legs 4 have an inner plane fa e l0, inclined upwardly and inwardly. Short stub shafts II project from. the faces ID at approximately right angles thereto. Between these shafts II is a bridge member l2 the ends of which are enlarged and formed with sockets to engage over the shafts II. The outer peripheries of the ends of said bridge are cylindrical at l3 to form a race for roller bearings it upon which the toothed cutters l5 are rotatable I prefer to place washers it between the cuttersand the wall faces in to take up the wear. As will be seen, I form a shoulder at I! on the inner side of the bearing to form a lateral thrust support for the bearings and cutters.

The intermediate portion of the bridge I! is flattened into a web ill from which project opposite aligned shafts l9. As will be seen from Fig. 3, the web is set slightly off center so that one shaft l 9 is slightly longer than the other and will hence support a longer-cross roller cutter 20. The ends of the shafts l9 are adapted to fit within grooves or notches 2| in the legs 3. The lower portion of the notch is then closed with a bond of welding material 22 which when in position closes the lower end of the split 6 in the bit, as will be seen in Fig. 3.

The cross roller cutters 20 are preferably, al- I I8 and into openings in the legs 3, said openings being closed-below the same as shown at 26. The

- cross roller cutter shaft is then held securely by a bond of welding material 24 at the ends, as seen in Fig. 5. d

When this bit is assembled, the cutters and bearings are fitted in position upon the bridge member and the cross roller shaft. The two halves of the head are then put together with the, shafts II engaging in the ends of the bridge member.. The ends of the shaft l9 will be received in notches 2|. The parts of the head are then welded together and the cross roller shaft i9 is welded in place by the weld 22. Whenthe shank 2 is screwed into the drill collar, the head is held together so that there is no danger of the head coming apart in use.

It will be seen that the parts may be quickly disassembled by the use of a torch to cut away the welds. The bit may be easily repaired in the field and new sets of cutters and shafts may be quickly installed. The drill has the further advantage that the cutters are firmly mounted and strongly supported.

What I claim as new is:

1. A cross roller bit including a head. inwardly extending shafts on said head at the forward end thereof, a bridge having sockets fitting over the ends of said shafts, side cutters mounted for rotation on the opposite ends of said bridge, a

cross roller shaft transversely of said bridge,

supports for the ends of said cross roller and cutters on said cross roller shaft.

2. A cross roller bit including a head, inward- 1y extending shafts on said head at the forward end thereof, a bridge having sockets fitting over the ends of said shafts, side cutters mounted for Shaft rotation on the opposite ends of said bridge, a I

tudinally of said head, a bridge having sockets fitting over the ends of said shafts, side cutters mounted for rotation on the opposite ends of said bridge, across roller shaft transversely of said bridge, supports for the ends of said cross roller shaft and cutters on said cross roller shaft.

4. A drill comprising a head, a recess in the lower end thereof having two opposed upwardly converging walls, inwardly projecting stub shafts on said walls, a supporting bridge extending transversely across said recess, upwardly and cutwardly inclined sockets at the ends of said bridge to engage over said stub shafts, bearings on the ends of said bridge, side cutters on said bearings, a cross roller shaft supported by said bridge midway the ends of said bridge, supports in said head for said cross roller shaft, and cross roller cutters on said cutter shafts.

5. A drill comprising a head, a recess in the lower end thereof having two opposed upwardly converging walls, inwardly projecting stub shafts on said walls, a supporting bridge extending transversely across said recess, sockets formed in the ends of said bridge engaging over the ends of said stub shafts, bearings on said bridge adjacent said shafts, cutters, on said bearings, a cross roller shaft supported by and extending laterall'y from said bridge and cross roller cutters on said cross roller shaft.

6. A drill comprising a head having a recess in its forward end, opposite downwardly flaring walls in said recess, stub shafts projecting inwardly at approximately right angles to said inclined walls, a bridge extending across said recess and supported at its ends on said shafts, cutters rotatable upon the ends of said bridge, a cutter shaft extending across said recess approximately at right angles to said bridge, and cutters on said cutter shaft.

'7. A drill comprising a head having a recess in its forward end, opposite downwardly flaring walls in said recess, stub shafts projecting inwardly at approximately right angles to said inclined walls, a bridge extending across said recess and supported at its ends on said shafts, cutters rotatable upon the ends of said bridge, a. cutter shaft extending across said recess approximately at right angles to said bridge, and a cross roller cutter on each end of said cutter shaft, one of said cross roller cutters being longer than the other.

NELSON B. BERLETI-I. 

